上颌组牙三维有限元模型的建立及Carrière Distalizer矫治器的力学分析

Building of 3D maxillary canine and molar with natural ranking finite element model and mechanical analysis of Carrière Distalizer adjusting appliance

目的建立一侧有效的自然排列的上颌尖牙和第一磨牙及周围牙槽骨的三维有限元模型,分析在Carrière Distalizer矫治器作用下,组牙的应力分布及其位移特点。方法通过螺旋CT扫描获得精确的组牙及颌骨DICOM格式的图像信息,采用Mimics三维建模软件和Ansys有限元分析软件建立及拟合上颌骨中正常位置的上颌组牙及其周围牙槽骨的三维有限元模型,模拟Carrière Distalizer矫治器的力学实验并进行相关分析。结果成功建立了上颌组牙及其周围牙槽骨的三维有限元模型。力学实验显示,尖牙和磨牙颈部剖面腭侧应力分布及位移明显小于颊侧、远中和近中,表现为类似旋转移动的柱状图形;而尖牙和磨牙整个远中剖面的应力分布及位移规律基本相同,均表现为自牙颈部向牙根部逐渐衰减的倾斜移动的曲线。结论本实验创建的上颌组牙及其周围牙槽骨的三维有限元模型,达到了几何外形和生物力学的相似性,可用于精确的生物力学分析;尖牙和磨牙在CD的作用下,应力分布及位移规律均呈现有旋转和倾斜移动的趋势。

Objective To set up 3D finite element models of maxillary canine and molar with natural ranking among the group teeth and to analyze their stresses and displacements caused by the use of Carrière Distalizer. Methods Helix CT scans were taken for teeth and alveolar bone samples to get legible and accurate DICOM image information. 3D models of maxillary canine and molar and of maxilla alveolar bone were generated by Mimics 3D modeling software and Ansys finite element software. 3D finite element analysis was performed on the established model to compare the Von Mises stresses and displacements. Results 3D models of canine and first molar with normal ranking in maxillary and of maxillary alveolar bone in the same side were generated respectively by Mimics 3D modeling software and Ansys finite element software. The load experiment showed that the stresses and displacements of distal and buccal plane around cervical section plane of canine and molar were more prominent. But on the distal plane of canine and molar,the curves of the stresses and displacements were similar in shape. Conclusion The models of maxillary canine and first molar with normal ranking and their ambient alveolar bone could be generated by Mimics and Ansys software, exhibiting similarity in geometry and biomeehanies. Canine and molar showed the trend of rotation and incline movement caused by the use of Carrière Distalizer.